This study is designed to evaluate the efficacy, safety, and pharmacokinetics (PK) of perampanel on Primary Generalized Tonic Clonic (PGTC) seizure frequency in adolescents and adults maintained on one to two stable antiepileptic drugs.

Percent change from baseline in PGTC seizure frequency per 28 days [ Time Frame: from baseline over the Titration and Maintenance Periods (17 weeks), extension period (38 weeks) ] [ Designated as safety issue: No ]

Secondary Outcome Measures:

Responder Rate for all subtypes of primary generalized seizure frequency per 28 days [ Time Frame: Maintenance Period relative to baseline (17 weeks), extension period (38 weeks) ] [ Designated as safety issue: No ]

Clinical diagnosis of PGTC seizures (with or without other subtypes of primary generalized seizures) and experiencing greater than or equal to 3 PGTC seizures during the 8-week period prior to randomization

Have had a routine electroencephalogram (EEG) prior to or during the Baseline Period with electroencephalographic features consistent with primary generalized epilepsy; other concomitant anomaly should be explained by adequate past medical history

On a fixed dose of one to a maximum of three concomitant antiepileptic drugs (AEDs) for a minimum of 30 days prior to Baseline; only one inducer AED (i.e., carbamazepine, oxcarbazepine, or phenytoin) out of the maximum of two AEDs will be allowed

A vagal nerve stimulator (VNS) will be allowed, but it must have been implanted greater than or equal to 5 months prior to Baseline (stimulator parameters cannot be changed for 30 days prior to Baseline and for the duration of the study).

Have had a computed tomography (CT) or magnetic resonance imaging (MRI) within the last 10 years (for adults) and 5 years (for adolescents) that ruled out a progressive cause of epilepsy

A ketogenic diet will be allowed as long as the subject has been on this diet for 5 weeks prior to randomization

Exclusion:

A history of status epilepticus that required hospitalization within 12 months prior to Baseline

Seizure clusters where individual seizures cannot be counted

A history of psychogenic seizures

Concomitant diagnosis of Partial Onset Seizures (POS)

Progressive neurological disease

Clinical diagnosis of Lennox-Gastaut syndrome

If felbamate is used as a concomitant AED, subjects must be on felbamate for at least 2 years, with a stable dose for 60 days prior to Baseline. They must not have a history of white blood cell (WBC) count below less than or euqal to 2500/microL (2.50 1E+09/L), platelets less than 100,000/microL, liver function tests (LFTs) greater than 3 times the upper limit of normal (ULN), or other indication of hepatic or bone marrow dysfunction while receiving felbamate.

Concomitant use of vigabatrin: Subjects who took vigabatrin in the past must be discontinued for approximately 5 months prior to Baseline, and must have documentation showing no evidence of a vigabatrin-associated clinically significant abnormality in an automated visual perimetry test

Concomitant use of barbiturates (except for seizure control indication) within 30 days prior to Baseline

Use of intermittent rescue benzodiazepines (i.e., one to two doses over a 24-hour period considered one-time rescue) two or more times within the 30 days prior to Baseline

Contacts and Locations

Choosing to participate in a study is an important personal decision. Talk with your doctor and family members or friends about deciding to join a study.
To learn more about this study, you or your doctor may contact the study research staff using the Contacts provided below.
For general information, see Learn About Clinical Studies.

Please refer to this study by its ClinicalTrials.gov identifier: NCT01393743